# time

From cppreference.com
< c‎ | chrono

Defined in header ``<time.h>`` |  |
time_t time( time_t* arg ); |  |

Returns the current calendar time encoded as a time_t object, and also stores it in the time_t object pointed to by arg (unless arg is a null pointer)

### Parameters

arg | - | pointer to a time_t object where the time will be stored, or a null pointer

### Return value

Current calendar time encoded as time_t object on success, (time_t)(-1) on error. If arg is not a null pointer, the return value is also stored in the object pointed to by arg.

### Notes

The encoding of calendar time in time_t is unspecified, but most systems conform to POSIX specification and return a value of integral type holding the number of seconds since the Epoch. Implementations in which time_t is a 32-bit signed integer (many historical implementations) fail in the year 2038.

### Example

Run this code

    #include <stdint.h>
    #include <stdio.h>
    #include <time.h>

    int main(void)
    {
        time_t result = time(NULL);
        if (result != (time_t)(-1))
            printf("The current time is %s(%jd seconds since the Epoch)\n",
                   asctime(gmtime(&result)), (intmax_t)result);
    }

Possible output:

    The current time is Fri Apr 24 15:05:25 2015
    (1429887925 seconds since the Epoch)

### References

- C23 standard (ISO/IEC 9899:2024):

  - 7.27.2.4 The time function (p: TBD)

- C17 standard (ISO/IEC 9899:2018):

  - 7.27.2.4 The time function (p: 286)

- C11 standard (ISO/IEC 9899:2011):

  - 7.27.2.4 The time function (p: 391)

- C99 standard (ISO/IEC 9899:1999):

  - 7.23.2.4 The time function (p: 341)

- C89/C90 standard (ISO/IEC 9899:1990):

  - 4.12.2.4 The time function

### See also

localtimelocaltime_rlocaltime_s (C23)(C11) | converts time since epoch to calendar time expressed as local time (function)
gmtimegmtime_rgmtime_s (C23)(C11) | converts time since epoch to calendar time expressed as Coordinated Universal Time (UTC) (function)
timespec_get (C11) | returns the calendar time in seconds and nanoseconds based on a given time base (function)
C++ documentation for time

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